Flickr - Free photo sharing and collaboration tool that allows pictures to be kept "private" or shared with a group. If you or your students are looking for pictures that can be legally downloaded and used in presentations, make sure to check out Flickr Creative Commons.
Google Calendar - Outstanding calendaring application. Allows you to share your calendar (or parts of your calendar) with other users.
Google Docs & Spreadsheets - Online word processor and spreadsheet. Allows collaboration by multiple users on a single document. Save to your computer, or leave it online and access it from anywhere.
Google Notebook - Outstanding tool for research and collaboration.
Google Reader - RSS feed reader for keeping on all the blogs and news sites you're reading.
Picnik - Browser-based photo editing. Similar in functionality, if not a bit more polished, to Snipshot.
Slideshare - Got a PowerPoint presentation you'd like your students to be able to view form somewhere other than your classroom? Upload it to Slideshare and it can be accessed from anywhere with an Internet connection.
Snipshot - Browser-based photo editing. No downloads and nothing to install. Point to a pic on the Web or upload one of your own.
Zoho - Web-based word processor, spreadsheets, presentations, wikis, and notebooks with some amazing possibilities for collaboration. Watch a short video demo here.
21Classes - Host and manage blogs for you and your students. Free for up to 50 students (2 MB capacity each) or $8.95 per month for up to 100 students (25 MB capacity each).
Tech Tools for Teachers
This is an open Wiki so please feel free to add any that you have used and would recommend, along with a little "blurb" about what it does.Web 2.0 Productivity Apps
Start a Blog (Our demo blog)
Start a Wiki (Our wiki demo page and the outline of our mini-session on blogs and wikis)
Other Reference and Resources